Certificates Issued to Huawei Subsidiary Found in Cisco Switches

Researchers noticed that the firmware for some Cisco switches contains X.509 certificates and associated private keys issued to a US-based subsidiary of Huawei. An investigation by the networking giant revealed that it was an oversight related to the use of an open-source third-party component.

While conducting tests using its IoT Inspector tool designed for automated firmware security analysis, SEC Consult noticed that the firmware for Cisco SG250 Smart Switches contained some digital certificates and corresponding private keys in the /root/.ssh/ folder.

The certificates were issued to gary.wu1(at)huawei.com from Futurewei Technologies, a US-based subsidiary of Chinese tech giant Huawei. Huawei equipment has been banned from government agencies and infrastructure in the United States over concerns that the company could be aiding China’s espionage efforts.

Cisco was immediately notified by SEC Consult and within a few days it determined that the certificates existed in its firmware due to the use of an open-source package called OpenDaylight, which is designed for customizing and automating networks.

In an informational advisory published on Wednesday, Cisco says its FindIT development team uses OpenDaylight for testing purposes and the certificates should not have been included in production firmware.

“[The certificates and keys] were never used for live functionality in any shipping version of the product. All shipping versions of the Cisco FindIT Network Probe use dynamically created certificates instead. The inclusion of the certificates and keys from the OpenDaylight open source package in shipping software was an oversight by the Cisco FindIT development team,” Cisco explained.

The company says the issue impacts the firmware for Cisco Small Business 250, 350, 350X, and 550X series switches. Cisco has removed the certificates from its firmware and plans on addressing other issues found by SEC Consult in future firmware releases. These other issues found by SEC Consult include empty password hashes and unneeded software packages, but Cisco claims they apparently cannot be exploited as there is no way to access the affected parts of the system.

Cisco itself has also identified twovulnerabilities in the Small Business 200, 300 and 500 series switches. Classified as “high severity,” the flaws can be exploited by a remote, unauthenticated attacker to cause a denial-of-service (DoS) condition.

Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.